Jun 30, 2015

Penn State: Insect fruit pests update for July

By now at least one generation of codling moth, oriental fruit moth, tufted apple bud moth and or obliquebanded leafroller should be completed and if our management effort was successful, the pressure from consecutive generations should be much lower. The sex pheromone traps for all four major pest species remain the most reliable tools to assess the actual pressure from each pest and the best indicator “if” and “when” additional control measures need to be implemented.

Also, by now the populations of pear psylla, scales, aphids and mites should be under either effective biological control by beneficial organisms or already suppressed by applications of effective insecticides. However, as the weather become hotter and drier the conditions may be become favorable for a rapid increase of phytophagous mites populations. If needed, European red mite or twospotted mite can be controlled with a wide assortment of summer acaricides: Envidor (IRAC Group 23), Kanemite (IRAC Group 20B), Nealta (IRAC Group 25, registered only on pome fruit), Nexter (IRAC Group 21A) Portal (IRAC Group 21A) or Zeal (IRAC Group 10B). When deciding which products to use, please remember about resistance management and do not use products from the same IRAC group during two consecutive seasons.

The distribution of usual mid-summer pests such as Japanese beetle, leafhoppers or wooly apple aphids tends to be localized and actual management may be needed only in some isolated orchards. If management of JB or leafhoppers such white apple leafhopper (WALH) potato leafhoppers (PLH) and rose leafhopper (RLH) is needed, neonicotinoid insecticides should provide excellent control of these pests. Most materials recommended for the control of brown marmorated stink bug should also provide good control of JB. For WAA management, products such as Diazinon or Movento should provide effective control.

Unfortunately, July also marks the beginning of a much higher pressure from brown marmorated stink bug nymphs and summer adults. As of this week (June 25), we are finding third instar nymphs in some peach and apple orchards located in southern PA. The presence of BMSB nymphs in orchards means a shift from “probable BMSB injuries” to actual nymphal feeding and associated fruit injuries and the change from “migratory” pest status of BMSB adults to “resident” pest for nymphs. From July until November, traps baited with commercially available, BMSB lures are quite effective in detecting and capturing BMSB adults and nymphs. The attractiveness of commercial BMSB lure increases significantly in the later part of the season although we are already collecting BMSB adults and nymphs in both Ag-Bio and Rescue traps deployed in orchards. Commercial BMSB lures and traps are available from Ag-Bio Inc. and Sterling International, Inc. The list of effective insecticides against BMSB includes most pyrethroids, neonicotinoids and Lannate®.

Unexpected insect found in orchards

During last week we received two reports from western PA about previously not seen insect, resembling curculio observed on foliage of fruit trees. Based on the preliminary identification it appears to be yellow poplar weevil Odontopus calceatus (Coleoptera: Curculionidae) also known as sassafras or magnolia weevil. Although from the same insect family as plum or apple curculio, yellow poplar weevil is not known to cause any injuries to fruit or fruit trees. On its preferred hosts the injuries caused by yellow poplar weevil adults are limited to small holes in the leaves while the larval stage mines the leaves near the edges of the leaf forming an irregular blotch.

— By Grzegorz Krawczyk, Extension Tree Fruit Entomologist