This past July I observed tachinid flies around conglomerations of June bugs and Japanese beetles while tallying insects in industrial hemp fields (Figure 1). Yaziri Gonzalez (graduate student in Entomology) collected stink bugs in soybean fields in central and western Kentucky in August 24 and September 7 and found that 38% of the collected stink bugs were parasitized by tachinids (Figure 2). In September (sampling in the mid and later week) at a 15 day interval in hemp, we found that approximately 20% of collected corn earworm were parasitized by tachinids flies (see link) during two sampling dates.
Tachinids are flies (Diptera: Tachinidae) of great importance in the control of many insect pests. For most people, adult tachinids can be misidentified as a common house fly; however, tachinid flies are larger than a house fly and with great number of noticeable hairs. Nevertheless, tachinid flies range in size from 0.08 to 0.7 inch (2–20 mm), and across the family there is a tremendous variety of shapes, colors, and degree of bristling.
Tachinids have interesting and variable egg laying strategies. In the cases described above, the adult tachinid glued her eggs somewhere on the outside body of the stink bugs or corn earworms. Later on, eggs hatch and the maggots penetrate into the host’s body. Tachinids have one to multiple generations a year. The adult tachinid flies also feed on nectar or honeydew from aphids and soft scales. During the last past 3 years observation on the sugarcane aphid outbreaks in sorghum, many tachinids were observed feeding on the honeydew.
By Raul T. Villanueva, Extension Entomologist and Yaziri Gonzalez, Entomology Graduate Student.