Download Eastern Lubber Grasshopper, Romalea microptera (Beauvois

EENY-006
Eastern Lubber Grasshopper, Romalea microptera
(Beauvois) (=guttata (Houttuyn)) (Insecta: Orthoptera:
Acrididae)1
C. W. Scherer and J. L. Capinera2
Introduction
Periodically, grasshoppers have been of economic importance in Florida. A few species may occur in large enough
numbers to cause serious damage to citrus, vegetable
crops and landscape ornamentals. One of the species most
commonly causing damage is the eastern lubber grasshopper, Romalea microptera (Beauvois), also known as Romalea
guttata (Houttuyn).
Distribution
The eastern lubber grasshopper is limited to the southeastern and south central portion of the United States. The
northern boundary is central North Carolina west through
southern Tennessee, Georgia, Alabama, Mississippi,
Louisiana, Arkansas, to Texas. It occurs throughout Florida.
Description
The eastern lubber is surely the most distinctive grasshopper species in the southeastern United States. It is well
known both for its size and its unique coloration. The wings
offer little help with mobility for they are rarely more than
half the length of the abdomen. This species is incapable of
flight and can jump only short distances.The eastern lubber
is quite clumsy and slow in movement and mostly travels by
walking and crawling feebly over the substrate. The “lubber”
Figure 1. Distribution of Romalea microptera, the eastern lubber
grasshopper.
designation is interesting because it aptly describes this
grasshopper. “Lubber” is derived from an old English word
“lobre” which means lazy or clumsy. This term has come to
mean a big, clumsy, and stupid person, also known as a lout
or lummox. In modern times, it is normally used only by
seafarers, who term novices “landlubbers”. Eastern lubber
is one of only four species in the family Romaleidae found
north of Mexico, but there are many other species in South
America, and many are winged and agile, so although some
other species in this family are called lubbers, the “lubber”
designation is not appropriate for the entire family.
1. This document is EENY-006 (IN132), one of a series of Featured Creatures from the Entomology and Nematology Department, UF/IFAS Extension.
Published October 1996. Revised July 2013. This document is also available as a Featured Creature at http://entomology.ifas.ufl.edu/creatures.
Please visit the EDIS website at http://edis.ifas.ufl.edu.
2. C. W. Scherer, graduate assistant, and J. L. Capinera, professor/department chairman, Entomology and Nematology Department, Cooperative
Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611.
The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to
individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national
origin, political opinions or affiliations. U.S. Department of Agriculture, Cooperative Extension Service, University of Florida, IFAS, Florida A&M University Cooperative
Extension Program, and Boards of County Commissioners Cooperating. Nick T. Place , Dean
Eggs. Eggs are produced about a month after emergence of
the adults. According to Hunter-Jones (1967), females each
produce 3-5 egg clusters in structures called pods. The pod
is not much more than tightly packed eggs surrounded by
rigid, frothy material, with most of the froth deposited at
the tip of the pod closest to the surface. The froth allows an
easy exit for the young hoppers as they can readily wiggle
through this as they hatch. The interval between egg pod
production by a females is about 2 weeks. Hunter-Jones
reported egg production of 30-80 eggs per pod, averaging
about 60 eggs per pod. Egg production was greater under
solitary than crowded conditions. On the other hand, under
field conditions Stauffer and Whitman (2007) reported egg
production of 25-50 eggs per pod, with only 1-3 pods per
female. Egg production in the laboratory was greater than
in the field. The eggs require a cool period (e.g., 20°C for
3 months) but then will hatch when exposed to warmer
temperatures.
Figure 2. Young lubber, Romalea microptera (Beauvois), instar one. The
segments above the second and third legs bear wing buds, though at
this stage they are hardly visible.
Credits: Lyle J. Buss, University of Florida
Nymphs. The immature eastern lubber grasshopper differs
dramatically in appearance from the adults. Nymphs
(immature grasshoppers) typically are almost completely
black, but with a distinctive yellow, orange, or red stripe
located dorsally. The hopper’s face, edge of the pronotum,
and abdominal segments also may contain reddish accents.
Often the reddish accents change to yellow over the course
of development. When they first molt, the young hoppers
may be brownish, but they soon darken to black.
As they mature, the nymphs change slightly in appearance;
the instar is easily determined by examination of the developing wings. Initially (instars 1-3), the general orientation
of the wing tips is to point ventrally, whereas after the third
instar the orientation reverses, pointing dorsally. In the first
instar, the tips of the meso- and metathoracic wingbuds
are not elongated, and lack wing veins. In the second
instar, the wing buds develop weak evidence of veins along
the ventral margin, and in the third the mesothoracic
wings point slightly posteriorly but maintain their ventral
orientation. After the reversal of orientation, the wing buds
are discernable wings, albeit small. The wings of the fourth
instar barely extend posteriorly to reach the tympanum
(oval acoustic structure) and the anterior margin of the first
abdominal segment. The wings of the fifth instar extend as
far posteriorly as the posterior margin of the tympanum
and the posterior margin of the first abdominal segment.
Even in the fifth instar, however, the wing buds do not
overlap and cover the tympanum. In adults, the wings
overlap and cover the tympanum, extending posteriorly to
cover 3-4 abdominal segments.
Figure 3. Young lubber, Romalea microptera (Beauvois), instar two. The
beginnings of the wing veins can be seen now.
Credits: Lyle J. Buss, University of Florida
Figure 4. Young lubber, Romalea microptera (Beauvois), instar three.
Now you can better see the developing veins and a slight backward
(posterior) extension of the wing buds.
Credits: Lyle J. Buss, University of Florida
Eastern Lubber Grasshopper, Romalea microptera (Beauvois) (=guttata (Houttuyn)) (Insecta: Orthoptera: Acrididae)
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Figure 5. Young lubber, Romalea microptera (Beauvois), instar four.
Now you can see something that actually looks like a wing, although
it is quite small. Note that it is pointed upward (dorsally). Also note
its length relative to the oval, reddish-colored tympanum on the first
abdominal segment.
Credits: Lyle J. Buss, University of Florida
Adults. Adult males and females are usually 6.0 and 8.0 cm.
long, respectively. The body is quite robust while the legs
remain relatively slender. The general color of adults is dull
yellow with varying degrees of black spots and markings.
The front pair of wings (tegmina) are yellow with numerous
scattered black dots, while the hind wings when exposed
reveal a bright red/rose coloration with a black border. The
color of adult lubbers also varies throughout most of the
insect’s range. One phase is nearly entirely black (melanic)
with a few marks of yellowish. The adults of this melanic
phase seem to resemble the nymph, but only in color.
Individuals in the same geographic area may be yellowish,
melanic, or somewhere in between. However, despite their
different appearances, these different-appearing grasshoppers are the same species and will mate successfully.
The color of adult lubbers also varies throughout most of
the insect’s range. One phase is nearly entirely black with a
few marks of yellowish tawny. The adults of this phase seem
to resemble the nymph. However, the different phases are
indeed the same species.
Figure 6. Young lubber, Romalea microptera (Beauvois), instar five.
The wing is longer now, extending further posteriorly relative to the
tympanum. Next it will molt to the adult, though you cannot tell from
the nymph what color form will be assumed by the adult.
Credits: John Capinera, University of Florida
The nymphs often are found in aggregations, and ascend
vegetation to roost, especially at night. Presumably this
behavior removes them from ready access by night-active
ground-dwelling predators, though they reportedly are well
defended chemically (see defensive characteristics, below).
Figure 7. Lubber nymph Romalea microptera (Beauvois), molting,
leaving behind its old (darker) body covering.
Credits: Lyle J. Buss, University of Florida
Figure 8. Adult eastern lubber grasshopper, Romalea microptera
(Beauvois), light color phase.
Credits: John Capinera, University of Florida
Figure 9. Adult eastern lubber grasshopper, Romalea microptera
(Beauvois), intermediate color phase.
Credits: John Capinera, University of Florida
Eastern Lubber Grasshopper, Romalea microptera (Beauvois) (=guttata (Houttuyn)) (Insecta: Orthoptera: Acrididae)
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oviposition is highly variable, but ovipositing females select
open, sunny areas of higher elevation, then use the tip of
the abdomen to dig a small hole into a suitable patch of soil.
Usually at a shallow depth, but sometimes up to a depth of
about 5 cm, she will deposit her eggs within a light foamy
froth. These eggs will remain in the soil through late fall
and winter and then begin hatching in Spring. The young
grasshoppers crawl up out of the soil upon hatching and
congregate near suitable food sources. Lubbers are often
found in damp or wet habitats, but seek drier sites for
egg-laying.
Figure 10. Adult eastern lubber grasshopper, Romalea microptera
(Beauvois), dark color phase.
Credits: John Capinera, University of Florida
Figure 12. Mating adults of two color forms.
Credits: Lyle J. Buss, University of Florida
Figure 11. Black color form of adult eastern lubber grasshopper,
Romalea microptera (Beauvois).
Credits: Lyle J. Buss, University of Florida
Life Cycle
Adult Romalea microptera exist nearly throughout the year
in Florida with their numbers dwindling during the fall and
winter period. They have one generation per year, with eggs
beginning to hatch in February in South Florida while the
rest of the state usually doesn’t see this species until March
or later. Eastern lubbers, like all grasshoppers, molt and
grow repeatedly before attaining maturity. These immature
stages (instars) are referred to as nymphs. Lubbers normally
have a total of five instars before molting into the adult
stage, though some females have six instars. The length
of these instars varies with temperature, but at 30°C the
development times are about 10-12, 8-9, 10, 10, and 15-16
for instars 1-5, respectively (Hunter-Jones 1967). In Florida,
the highest number of adults can be observed during the
months of July and August.
After mating, females will begin laying eggs during the
summer months. The male usually guards the ovipositing
female, sometimes for more than a day. The timing of
Populations cycle up and down, possibly due to the action
of parasites. The tachinid fly Anisia serotina (Reinhard)
attains high levels of parasitism, sometimes 60-90%. We
have also found the sarcophagids Blaesoxipha opifera
(Coquillett) and Blaesoxipha hunter (Hough) parasitizing
this grasshopper, sometimes at high incidences of parasitism (unpublished; identified by G.A. Dahlem, Northern
Kentucky University). A gregarine parasite, Boliviana
floridensis (Protozoa: Eugregarinidia) can be found in their
gut (Stauffer and Whitman 2007).
Figure 13. One of the species of parasitic flies (Blaesoxipha hunteri)
that affects lubbers. The larvae develop within the nymphs, killing
their hosts when they emerge.
Credits: Lyle J. Buss, University of Florida
Eastern Lubber Grasshopper, Romalea microptera (Beauvois) (=guttata (Houttuyn)) (Insecta: Orthoptera: Acrididae)
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Habitat and Hosts
Defensive Characteristics
Eastern lubber grasshoppers seem to prefer open pinewoods, weedy fields and the weedy vegetation along
roadsides. Occasionally, on rural highways in the central
portion of the state, enough flattened lubber grasshoppers
will accumulate on the road to cause a minor slick. Watson
(1941) suggested that lubbers avoided both low, wet sites
and elevated, extremely dry sites when ovipositing. He
observed that the interface between mesic hardwood
communities and more xeric pine-dominated forests are
preferred oviposition sites.
Adults of eastern lubber grasshoppers possess a variety of
abilities to defend themselves. Their bright color pattern
is a warning to predators that the lubber contains toxic
substances. Indeed, there are several records attributing the
demise of individual birds failure to exercise caution when
selecting prey items. Also, small mammals such as opossums have been known to vomit violently after ingesting a
lubber, and to remain ill for several hours. However, shrikes
are reported to catch and kill lubbers.
The accumulation of weedy plant species along drainage
ditches within citrus groves and vegetable fields will
sometimes attract lubbers, which in turn end up feeding on
the cultivated crops as well. Lubbers often invade residential
areas and feast on flowering plants, especially amaryllis,
narcissus, and crinum (all family Amaryllidaceae) (Watson
1941). These grasshoppers will migrate long distances
to obtain preferred food, sometimes forming trails and
following one another. The host preferences of lubbers are
not well documented, though they clearly are generalists,
capable of feeding on many plants. Watson (1941) reports
that, in addition to the aforementioned flowers, they accept
tread softly, Cnidoscolous stimulosus (Euphorbiaceae) and
pokeberry, Phytolaca americana (Phytolaccaceae) in mesic
habitats, and pickerel weed, Pontederia cordata (Pontederiaceae), lizard’s tail, Saururus cernuus (Saururaceae),
broadleaf arrowhead, Sagittaria latifolia (Alismataceae),
and Cyperus (Cyperaceae) in moist or wet areas. The crop
most often affected in Florida is citrus, though typically it
is mostly the small, newly planted trees that are adversely
affected. Other fruit trees and many vegetables also are
susceptible to damage.
Young lubbers (various instars) in citrus grove. Video by
John Capinera, University of Florida.
Barbara and Capinera (2003) studied suitability of poison
bait for lubber control (see Management of Lubbers). As
part of this investigation, they compared the acceptance
of various vegetable crops to bran bait, thus obtaining
relative preference values for many crops. Crops in the
plant families Brassicaceae, Asteraceae, Cucurbitaceae,
and Apiaceae were relatively preferred by lubbers. Thus,
cauliflower, collards, lettuce, carrot, onions, and squash
were relatively favored by lubbers. In contrast, Solanaceae
was not very preferred, so peppers, tomatoes and eggplants
are less likely to be consumed.
If the red, yellow, and black coloration fails to keep a
predator at bay, when contacted the lubber may produce
a phenolic secretion from a special thoracic gland, first
as a dispersant spray and then as a frothy secretion. This
exudate consists of a number of phenolic and quinone
compounds, some of which are irritants or toxins that deter
predation by vertebrates and ants (Jones et al. 1987, Whitman et al. 1991). The exact nature of the toxic properties
varies, as these grasshoppers assimilate different compounds depending on the plants they ingest. This bubbly
froth is accompanied by a relatively loud hissing sound.
The insect contracts the abdomen to force air out of the
spiracles along with the defensive secretion. The sound is
produced as the spray is being forced out of these tiny holes
in the thorax called spiracles. These defensive behaviors
seem to be limited to the adult stage.
Management of Lubbers
The size of the eastern lubber grasshopper is a little
misleading when one considers they require far less food
material than most of the more injurious species of grasshoppers that are only one-third as large or smaller. Thus,
they do less damage than one might expect.
Grasshopper abundance can be regulated through management of the vegetation. If you deprive grasshoppers of their
favored food, often they will leave or perish. Keeping the
vegetation mowed is very helpful, as short vegetation does
not often support grasshoppers
Lubber grasshoppers will often develop initially in moist
areas around ponds and irrigation ditches, then later
migrate to homes, yards, and crops. Rather than waiting for
the grasshoppers to come to you, it is often best to take the
battle to them. So check potential breeding or feeding sites
for signs of grasshoppers. The young grasshoppers remain
clustered in groups, but as they get older they are more
likely to be solitary. If you cannot control them through
mowing, try hand-picking. You can throw them into a
bucket of soapy water or a trash bag to kill them.
Eastern Lubber Grasshopper, Romalea microptera (Beauvois) (=guttata (Houttuyn)) (Insecta: Orthoptera: Acrididae)
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Selected References
• Barbara, KA, Capinera JL. 2003. Development of a toxic
bait for control of eastern lubber grasshopper (Orthoptera: Acrididae). Journal of Economic Entomology
96:584-591.
• Blatchley WS. 1920. Orthoptera of Northeastern America.
Nature Publishing Company. Indianapolis, Indiana. p.
304-307.
Figure 14. Young nymphs of the eastern lubber grasshopper, Romalea
microptera (Beauvois), clustered on a citrus reset (young citrus tree).
Credits: John Capinera, University of Florida
If there are too many to control by hand-picking, insecticides can be applied. Lubber grasshoppers are not easy to
kill, even with insecticides, once they become large. Among
the insecticides that will kill lubber grasshoppers are many
pyrethroid insecticides. You likely will have to apply the
insecticide directly to the insects; the small amount of
insecticide residue remaining on sprayed plants may not be
adequate to kill the grasshoppers.
Insecticide-containing baits are often used for grasshopper
control. Bran bait containing corn oil and insecticide is
attractive to lubbers, and they will perish after eating only
a small amount of toxicant (Barbara and Capinera 2003).
However, if there is highly attractive vegetation the lubbers
will be less likely to eat the bait, so bait applications are
most effective when applied to areas lacking competitive
vegetation, or interspersed among less preferred vegetation.
For example, insecticide bait might be scattered on bare soil
surrounding a vegetable garden to encourage the hoppers
to consume bait before they contact the crops.
If insecticides are to be used, be sure to apply them according to the directions on the label of the container. Especially
if insecticides are applied to food crops or near water, it
is important to heed the directions. Many insecticides are
toxic to fish, so it is imperative that open water be avoided.
Florida Insect Management Guide for citrus
Florida Insect Management Guide for commercial foliage
and woody ornamentals
• Capinera JL, Scherer CW, Squitier JM. (September 1999).
Grasshoppers of Florida. http://entomology.ifas.ufl.edu/
ghopper/ghopper.html (September 1999).
• Griffiths JT, Thompson WL. 1952. Grasshoppers in citrus
groves. University of Florida Agricultural Experiment
Station Bulletin no. 496.
• Fasulo TR, Brooks RF. (1998). Grasshopper, katydid and
cricket pests of citrus. EDIS. http://edis.ifas.ufl.edu/ch056
(June 2004).
• Helfer JR. 1953. How to Know the Grasshoppers,
Cockroaches and Their Allies. WM.C. Brown Company
Publishers. Dubuque, Iowa. p. 100-101.
• Jones CG, Hess TA, Whitman DW, Silk PJ, Blum MS.
1987. Effects of diet breadth on autogenous chemical
defense of a generalist grasshopper. Journal of Chemical
Ecology 13:283-297.
• Kuitert LC, Connin RV. 1953. Grasshoppers and their
control. University of Florida Agricultural Experiment
Station Bulletin no. 516.
• Lamb MA, Otto DJ Whitman DW. 1999. Parasitism of
eastern lubber grasshopper by Anisia serotina (Diptera:
Tachinidae) in Florida. Florida Entomologist 82: 365-371.
• Rehn JAG, Grant Jr HJ. 1961. A Monograph of the
Orthoptera of North America (North of Mexico).
Monographs of the Academy of Natural Sciences of
Philadelphia. No. 12. Vol. 1. p.231-240. Wickersham
Printing Company. Lancaster, Pennsylvania.
• Stauffer TW, Hegrenes SG, Whitman, DW. 1998. A
laboratory study of oviposition site preference in the
lubber grasshopper, Romalea guttata (Houttuyn).
• Stauffer TW, Whitman DW. 2007. Divergent oviposition
behaviors in a desert vs a marsh grasshopper. Journal of
Orthoptera Research 16:103-114.
Florida Insect Management Guide for vegetables
• Watson JR. 1941. Migrations and food preferences of the
lubberly locust. Florida Entomologist 24:40-42.
Grasshoppers are much easier to control when they are
nymphs. As they mature, and grow larger, higher rates of
toxicants must be applied for effective control.
• Whitman DW, Billen JPJ, Alsop D, Blum MS. 1991.
Anatomy, ultrastruicture, and functional morphology
of the metathoracic tracheal defensive glands of the
Eastern Lubber Grasshopper, Romalea microptera (Beauvois) (=guttata (Houttuyn)) (Insecta: Orthoptera: Acrididae)
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grasshopper Romalea guttata. Canadian Journal of
Zoology 69:2100-2108.
• Whitman DW, Jones CG, Blum MS. 1992. Defensive
secretion in lubber grasshoppers (Orthoptera: Romalidae): influence of age, sex, diet, and discharge frequency.
Annals of the Entomological Society of America 85:
96-102.
• Wilkerson JL, Webb SE, Capinera JL, Fasulo TR. (2005).
Vegetable Pests II: Acari - Hemiptera - Orthoptera Thysanoptera. University of Florida/IFAS. CD-ROM. SW
181.
Eastern Lubber Grasshopper, Romalea microptera (Beauvois) (=guttata (Houttuyn)) (Insecta: Orthoptera: Acrididae)
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