26 July 2000
Volume 8: no. 3
The Dog days of summer are coming on and it's mostly `hot' in Mississippi. That means most of us are happiest inside, both day and night. I've been seeing some different insects this year than in many years in the past. Tiger beetles have exploded on the scene and they are almost everywhere you look. I've even had calls from folks wondering what kind of new pest these fast moving critters are. We have also had a larger than usual number of `Green hunter' ground beetles this summer. A few weeks ago they were climbing into the oak trees feeding on the outbreaks of oak leaf caterpillar and we had some calls about controlling those large beetles which were attacking the oaks. A number of folks were both surprised and pleased when they discovered that the beetles were good guys helping us with a problem which was almost impossible to address, otherwise.
As summer comes to an end, it's time for 4-H collections to be touched up and gotten ready for traveling to the fair. County Fairs are ideal places for displaying insect collections and fall show days are already here in some counties. 4-H Entomologists should take advantage of every opportunity to display insect collections.
There are a few tips to remember when submitting collections:
- Refurbish your collection, making sure that there are no `insect parts' in the bottom of the box. Replace old specimens (twirlers etc.) or those which are not correctly pinned with those you have caught this year.
- Be sure that the date and locality labels are on the pins first and that the common name is low enough below them so they can be read. It is permissable for the common name label to lie on the bottom of the box. (If you have access to a computer and printer make your labels small and print them.) As collections grow in size, it might be good to orient the labels on the pins so they are parallel to the specimen's body.
- Since your collection is going to be traveling around and may get bumped, you should set the pins firmly into the bottom of the display box. Hooked forceps work well.
- Replenish your scavenger protection! Add new pest strip pieces or moth crystals or balls to the box regularly keeping it protected from scavengers. The box should be kept closed as much as possible. Don't store the collection in direct sunlight.
- Place your name, county, club, number of Orders, number of specimens and year of collection on a piece of white tape across the top edge of the display box. This assists the judges in looking at your collection.
- Make your collection as neat and pleasing to the eye as possible. 120 to 150 specimens representing 12 to 15 Orders will often look better in a collection than many more insects jumbled together. Do not place more than two (1 male and 1 female) specimens of the same insect in your box.
Tiger beetles are voracious predators, chasing down and flying after their prey and using their sickle-shaped jaws to secure the victim. Many species have iridescent coloration. They are usually found on or near bare ground and often run afoul of people and their activities. These beetles may be making a comeback because of changes in farming practices, i.e. no-till farming. Tiger beetle larvae are also highly predaceous and sit in burrows waiting to ambush passing prey which they drag underground to devour.
There are approximately 100 species of tiger beetles in the US, included in four genera: Amblycheila, Omus, Megacephala, and Cicindela. The tiger beetle is referred to as the butterfly of the beetles.
Identification: Adults are to æ" long and are iridescent in colors ranging from blue to green to black. They are usually nocturnal and often easily caught in pitfall traps. Larvae are S-shaped, with dorsal abdominal hooks (segment 5) which are used to hold position in their vertical burrows.
- Eggs: Eggs are deposited singly in shallow depressions.
- Larvae: The 1st instar larva digs a vertical burrow in which it will remain until pupation and adult emergence. Before each molt the larva plugs its burrow. Some species have adapted to surviving long periods of flooding (river species). Burrows range in depth from 8-10 inches to several feet, the extreme example being that of C. lepida whose larvae have been found to burrow six feet.
- Adults: Adults of most species occur only during the summer months. While a few species occur only during the cooler months in southern states, like Florida. Larvae occur during late summer and overwinter as last instars. Pupation probably occurs in springtime for summer species. Larvae occur in same habitat as adults for many species, or are found in close proximity to adult habitats for those species that occur in wet areas.
Parasites and Predators: Tiger beetles are parasitized as larvae by the Diptera family Bombyliidae and the Hymenoptera family Tiphiidae. They also are regularly preyed upon by robber flies of the Diptera family Asilidae.
Additional information about this unique creature may be found in - The biology of tiger beetles C.B. Knisley & T.D. Schultz.
Front / Back View:
Cutting The Lumber:
In recent weeks I have received a number of requests for general plans for a butterfly house. I found these on the WWW. Build the house out of untreated lumber and set it up in your garden prior to the fall. This is supposed to serve as a site for adult butterflies to hibernate. Place the shed bark from a tree in the box for the butterflies to attach themselves.
Needed Materials: thick cardboard (10"X 10") to cover trap, hand spade, several plastic containers with lids or resealable plastic bags, empty large (6 oz.) glass baby food jars (larger containers may be used); 1/2 oz. of one or more of the following baits: apple, meat, cheese, peanut butter, syrup; small flat stones, rubber stoppers or blocks of wood approximately 1/2" square, larger rocks to keep cardboard covers from blowing away.
- Choose a location for your pitfall traps. Look for places that will not get a lot of interference from people or large animals.
- Add bait to the first baby food jar.
- Write the name of the bait and location on the jar.
- Use the hand spade to dig a hole in the ground the same size as the jars being placed at each selected location.
- Place the open baby food jars into each of the holes and check that the top of each jar is at ground level. If the top edge it is not at ground level, take it out and add or remove more soil until it is.
- Add soil carefully to fill any gaps around the top of the jar.
- Place 4 small stones (rubber stoppers, wood blocks) in a 10" square around each jar and place a piece of cardboard on top of the stones. This will act as a roof to protect trapped animals from rain and direct sunlight.
- Put a larger stone on the cardboard to keep it from blowing away.
- Repeat the above steps for all of the jars you plan to use. Remember to leave one pitfall trap containing no bait at each site for a control, just to see what you might catch without bait.
- After 24 hours return to the traps.
- Remove the jars from each of the holes and be sure to record the location.
This idea was taken from Students in a Project-based Learning Approach to Schoolyard Habitat Development (SPLASHD) Bellvue, Illinois.
`Greenhunter' ground beetle
Dr. Michael R. Williams
Entomology & Plant Pathology
Mississippi State, MS 39762-9775
phone - 601-325-2085
home - 601-323-5699
FAX - 601-325-8837