Other Insects
Pecan Spittlebugs - The spittlebugs are currently overwintering on the bark of small stems as eggs and will hatch out and start feeding on the newly emerging twigs at budbreak.

A white mass of frothy insectine exudate often covers the nuts and new shoots of the pecan tree in the spring and summer. This is the mass of foam that covers the nymphs of the pecan spittlebug, Clastopera achatina Germar (Homoptera: Cercopidae). How the foam is produced is still not completely clear. As the nymph feeds on plant sap from the xylem, a mixture of water from the gut, a viscous substance from the excretory system and air from respiration forms the foam. The foam presumably functions to protect the nymphs from predators. Low populations where less than 5-15% of the nut bearing terminals have spittle masses can be tolerated, but higher populations of these bugs will interfere with pecan production by causing significant dieback of the shoots, interfering with the development of the nutlets. In Georgia, Tedders (1995, J. Econ. Entomol. 88(6):1641-1649) describes the life history in great detail. A brief synopsis has the season beginning with the hatching of the overwintering eggs one week after budbreak (late March to early April). The nymphs feed on the new growth and mature. Adults typically emerge from late May to early June. The eggs are oviposited in the new shoots near the leaf buds and bases of the nutlets, and on the thick parts of the leaf (rachis and midrib of the leaflet). The resulting nymphs produce large spittle masses as they feed near the oviposition sites in late June and July. The next generation of adults emerges during July and produces eggs for the second generation. Second generation infestations of nymphs are most apparent as full grown nymphs with large spittle masses in late August to late September. Adults typically emerge in early to mid-September and the females produce the overwintering eggs. Spittlebugs are cold blooded insects and continue to develop as long as the ambient temperature is high. A third generation could occur if the Fall climate is warmer than usual but this has not been found to be the case so far. There is a great deal of season to season variability in the abundance of spittle bugs. Tedders monitored adults with sticky traps during 1980 (extreme drought and high temperatures) and 1994 (extreme rain (flooding) and lower temperatures) and found that insects were more abundant in the Spring in 1980 and more abundant in the Fall in 1994. Apart from these two seasons with extreme conditions, spittlebugs typically start out at a lower abundance in the Spring and increase in the Summer and increase again in the Fall. Adult abundance was also found to be much higher in the top of the tree than in the middle or lower areas of the tree crown. This is not surprising given the dispersal ability of adults and the increase abundance of fresh shoots at the top of the tree. Spittlebugs jump. Spittlebugs jump high. In fact, proportional to their body size spittlebugs jump higher than any other living thing. Through a unique leg-locking mechanism, a set of large thoracic muscles and large spines on the legs, spittlebugs can jump 100 times their body length. The jump generated by the accumulation of energy in the large muscles in the thorax onto the short legs produces a take-off velocity of ~10 ft/sec creating a force of 400G on the insect’s body, sailing the insect to a distance of ~ 2 ft. (Burrows 2003, Nature 424: 509). That’s analogous to a person leaping over a 70 story skyscraper. What can be done to combat a spittlebug infestation? Climate and natural enemies apparently are effective at times but it’s not a predictable control. Is a spray needed or not? Yes, if 5-15% of the nut bearing terminals are infested. Nymphs feeding on the xylem tissue that transports water from the roots to the shoots and there is some indication that the feeding is associated with damage to the vascular system and nut loss. If a spray is needed when is the best time to spray? Population development is sporadic. High populations can crash due to natural controls and not be a problem for several seasons. However, certain orchards have high populations every season. For the sporadic infestations, spray closer to the 15% infestation level as the population may crash. For chronic infestations, spray closer to the 5% infestation level to knockdown the population before it develops into an outbreak. Consult your state recommendations for the best insecticide for control. There are several insecticides that effectively control spittlebugs.

Prionus root borers - Two species of rounded headed wood boring inssects attack pecan roots and can cause considerable damage albeit over a long period of time. Attempts to control the insects have not been very efective. Cultural controls include: 1. removing water stress from the trees with supplemental irrigation to encourage new root growth and increase water uptake in undamaged portions of the root system; 2. cutting back the top of severely damaged trees so that the root system will dieback and regenerate as the crown rejunvenates. This takes several years. Biological controls with soil born diseases and nematodes have not been attempted since lab studies indicate that the larvae are not highly susceptible to insect pathogens. Chemical controls in cherry trees are effective when the trunk and soil around the trunk are treated with Lorsban (4E (Dow AgroSciences)at 1.5 qt/100 gal of a directed spray to the trunk and soil four feet out from the trunk in two applications 14 days apart during adult emergence. Adults emergence is monitored by trapping the adult males with a blacklight trap. Adults are active during the summer from June to August.

Gregarious caterpillers need to be controlled before they migrate to the ground and pupate. Walnut caterpillars in the last instar in Tift Co., Fall webworms still have a week or so before they pupate. +++++++