Bugs for Growers — Natural enemies

Chinch bugs: one the most severe pests of turf foliage

How to identify Chinch bugs?

Chinch bugs are true bugs as they have piercing and sucking type of mouthparts i.e. long slender beak used for sucking cell sap from grass leaves. Young stages of chinch bug are called nymphs. Newly hatched nymphs are yellow in color but their color or body markings changes from yellow to reddish-black to orange-black as they molt from one stage to other stage during development. Also, with each molt nymphs more closely look like the adults. Chinch bug adults are about 1/6 inch long, and black and white in color.

Life cycle of chinch bugs:

Chinch bugs develop through three different stages: Egg, nymph and adult. These bugs over-winter as adults in protected areas such as under shrubs, in leaf litter and thick thatch layers. In the spring, the overwintering Chinch bug adults resume feeding on new turfgrass growth and at the same time start mating. After mating, females begin laying eggs. During a life span of usually 40 to 50 days, each female lay over 300 eggs on the grass leaves or stems near the ground. Under optimal environmental temperatures, eggs hatch within 7-15 days. Immediately after hatching from eggs, chinch bug nymphs start feeding on grass foliage. While feeding on grass over the period of 4 to 6 weeks, nymphs molts (shed its cuticle) 5 times, and go through 5 stages (instars) of development and become adults (6^th stage). These adults begin mating and start laying eggs from July through August. Then as stated above, after hatching from eggs, the second generation nymphs feed through October and go though different stages of growth, and become adults, which are ready for overwintering when cool temperature sets in.

Damaging stages of chinch bugs:

All six nymphal stages of chinch bugs cause damage to grass or other host plants. Adult chinch bugs also cause serious damage to grasses.

How chinch bugs cause damage to turf?

All the stages including adults of chinch bugs feed on a variety of grasses such as bentgrass, Kentucky bluegrass, perennial ryegrass, and red fescues. Both adult and nymphs of chinch bugs cause damage by sucking cell sap with their long slender beak from grass leaves.  While feeding they also inject toxins into grass leaves that causes clogging of leaf vascular system and affecting translocation of water and nutrients.  In case of severe infestation of chinch bugs, irregular brown patches of dead grass are noticed in the sunny areas of lawns.

Biological control of chinch bugs:

Natural enemies such as ants, big eyed bugs (Geocoris uliginosus), earwigs, ground beetles (see photo below), spiders, red imported fire ants (Solenopsis invicta) and wasps (Eumicrosoma benefica) help to suppress the populations of chinch bugs.  Entomopathogenic nematodes (Steinernema carpocapsae) and fungi (Metarhizium anisopliae and Beauveria bassiana) have a potential to manage chinch bugs. [caption id="attachment_257" align="alignright" width="300" caption="Ground beetles are natural enemies of chinch bugs"][/caption]

What stages of chinch bugs can be attacked by natural enemies?

Entomopathogenic nematodes can attack both adults and nymphal stages whereas entomopathogenic fungi can attack all the life stages including eggs of chinch bugs.  Also, predatory big eyed bugs can feed on all the stages of chinch bugs.

Buy Steinernema carpocapsae Nematodes

Literature:

Baxendale, F.P., A.P. Weinhold, and T.P. Riordan. 1994. Control of Buffalograss chinch bugs with Beauvaria bassiana and entomopathogenic nematodes, 1993. Nebraska insect management and insecticide efficacy reports, Dept. of Entomology Report No. 18, Univ. of Nebr., p. 43. Carstens, J.D., Baxendale, F.P., Heng-Moss, T. M. and Wright, R.J. 2008. Predation of the Chinch Bug, Blissus occiduus Barber (Hemiptera: Blissidae) by Geocoris uliginosus (Say) (Hemiptera: Lygaeidae). Journal of the Kansas Entomological Society 81: 328-338. Cherry, R. 2001.  Interrelationship of ants (Hymenoptera : Formicidae) and southern chinch bugs (Hemiptera : Lygaeidae) in Florida lawns.  Journal of Entomological Science 36: 411-415. Cherry, R. 2005. Interrelationship of big-eyed bugs (Hemiptera: Lygaeidae) and southern chinch bugs (Hemiptera : Lygaeidae) in Florida lawns. Journal of Entomological Science 40: 385-389. Samuels, R.I. and Coracini, D.L.A. 2004. Selection of Beauveria bassiana and Metarhizium anisopliae isolates for the control of Blissus antillus (Hemiptera: Lygaeidae). Scientia Agricola 61: 271-275. Samuels, R.I., Coracini, D.L.A., dos Santos, C.A.M. and Gava, C.A.T. 2002.  Infection of Blissus antillus (Hemiptera: Lygaeidae) eggs by the entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana.  Biological Control 23: 269-273.