Extension Entomology

Chilli thrips

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Article author: Scott Ludwig, Carlos Bogran
Most recently reviewed by: Extension Entomologist at Overton (2018)

Common Name(s): Chilli Thrips

Pest Location

Landscape Ornamental, Greenhouse Ornamental and Nursery, Vegetable and Fruit

Description

Chilli thrips are extremely small and difficult to distinguish from other thrips species without the aid of a compound microscope. Adults are pale with dark wings and less than 2 mm in length. Immature chilli thrips are also pale in color and resemble the immatures of many other thrips species. Infestations by chilli thrips are usually first detected in the landscape by the distinctive damage caused to the host plants. Unlike flower thrips, that feed primarily on pollen, chilli thrips feed on various plant tissues. Feeding causes leaf, bud, and fruit bronzing (tissues turn bronze in color). Damaged leaves may curl upward and appear distorted. Infested plants become stunted or dwarfed and leaves may detach from the stem at the petioles in some plant species. Feeding may also cause buds to become brittle and drop. Young leaves, buds and fruits are preferred, although all above ground parts of their host plants may be attacked. Plants with the symptoms described above should be examined closely for the presence of thrips.

 

Origin and Distribution

Chilli thrips, Scirtothrips dorsalis (Hood), is an important pest of crops in tropical and subtropical regions. An established population of this pest was first detected in the United States on landscape roses in Florida in 2005. In November 2007, chilli thrips were identified on landscape roses in Houston. Chilli thrips have also been detected on a number of ornamental and vegetable plants in retail stores in Northeast and South Texas.

Habitat & Hosts

Chilli thrips have a very broad host range and may feed on more than 150 plant species in 40 plant families. Additional plant species may be added to the list as this pest continues to expand its geographical range. The list includes many commonly grown landscape plant species (Table 1) and many important food and fiber crops. In Florida some of the most common plants attacked in the landscape are roses (Figure 1, 4-5), schefflera, Indian hawthorn (Figure 6), and pittosporum.

Life Cycle

The life cycle of chilli thrips is similar to that of other common thrips species, such as the western flower thrips. Egg to adult development is completed within 12 to 22 days, depending on temperature and host plant species. Females insert their eggs inside plant tissue on or near leaf veins, terminal plant parts and floral structures. Eggs hatch in 6–8 days under optimal conditions, but may take longer at lower temperatures. Immature thrips pass through two larval stages (1st and 2nd instars). The first instar lasts for 2-4 days and the second instar is completed in 3-6 days. During this time larvae actively feed on tender young plant growth, consuming enough food to complete development to the adult stage. Fully-grown larvae molt into a non-feeding, prepupal stage, which may last up to 24 hours, and then pupate on protected plant parts, leaf litter or in the soil near the base of the plant. The pupal stage lasts 2–3 days. In all, chilli thrips may complete their life cycle in 12 to 22 days and females generally deposit 60 to 200 eggs in their lifetime.

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Carpenter bee

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Most recently reviewed by: Janet Hurley & Pat Porter (2018)

Common Name(s): Carpenter Bee

Pest Location

Urban Structural

Description

Adult carpenter bees are large (3/4 to 1 inch long) and resemble bumble bees except that the abdomen is hairless and shiny black rather than being covered by patches of orange to yellow hair found on bumble bees. The carpenter bees in the genus, Ceratina, are much smaller (1/4 inch) and are dark bluish-green, and make nests in plant stems.

Carpenter bees are usually shiny or metallic blue-black with a greenish to purplish sheen. Some male carpenter bees have yellow areas on the face, and males of a few species may be partially to entirely buff or pale yellow.

Carpenter bees can be distinguished, however, by the lack of hairs on the top of the abdomen. On the rear legs, female carpenter bees have a dense brush of hairs, whereas female bumble-bees have large pollen baskets.

Origin and Distribution

Adult female carpenter bees can sting but usually only if aggressively disturbed; most carpenter bees “attacking” people passing by nesting sites are territorial males incapable of stinging,

Habitat & Hosts

Structural damage produced by nest-making activities can be somewhat damaging to homes, garages, fences and other buildings, although damage is largely cosmetic unless nesting sites are used repeatedly over years.

They prefer unfinished softwoods such as redwood, cypress, cedar and pine in structures for constructing nests. Carpenter bees do not consume wood like termites, but use wood merely to construct nests. While gathering nectar and pollen carpenter bees pollinate flowers.

Life Cycle

Complete metamorphosis. Adults spend the winter in nests constructed the previous year, and become active in April or May. After mating, females construct new nesting tunnels or use pre-existing tunnels. Nesting tunnels are about ½ inch wide and start on the end of wooden beams or at right angles to a surface for ½ to 1 inch before turning and following the wood grain. Tunnels are clean cut and may extend 6 to 8 inches. Females collect pollen and nectar to produce a dough-like mass called “bee bread.” Eggs hatch into larvae that feed on the bee bread in their cells. Development varies with species and temperature, but can progress from egg to adult in a little over a month. There may be two or three generations per year. Continuous generations may occur in south Texas. Adults emerging in late summer or fall do not mate until spring but may gather and store pollen in their tunnels.

Carpenter bee nests are easily distinguished from those of other wood-boring insects. Nest entrances are almost perfectly round and, for the common carpenter bee, about 1/2 inch in diameter. No other insect produces as large an opening with a perfectly round shape.

Management

If you live in the State of Texas, contact your local county agent or entomologist for management information. If you live outside of Texas, contact your local extension for management options.

Carpenter bees drill into wooden surfaces such as window sills, wooden siding, eaves, deck railings, outdoor furniture and fences which can be significant. Carpenter bees will attack painted or stained wood surfaces though bare wood is preferred. Carpenter bees do not consume wood like termites, but use wood merely to construct nests.

There are some paint additives that are insecticides, but a less permanent method of control would be to spray the bees with insecticide as they enter or exit the wood surface. Existing tunnels should be filled with stainless steel steel wool and caulk so as to prevent their re-use in the future.

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Carpenter Bees. Texas Apiary Inspection Service.

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