Tag: Clover

Insect of the Week – Pea aphid (Hemiptera: Aphididae)

This week’s insect of the week is the pea aphid (Acyrthosiphon pisum). This long-legged, pear-shaped aphid is 3-4 mm long, light to dark green and each antennal segment is tipped by a black band. It feeds on field peas, alfalfa, broad beans, chickpeas, clover and lentils. Feeding damage can reduce yields due to lower seed formation and seed size. Leaves may turn yellow and overall plant growth can be delayed.

Pea aphids overwinter as eggs on the leaves and stems of perennial legumes (eg. clover or alfalfa crowns). They produce 2-3 generations asexually before winged females migrate to summer host crops where several more generations are produced. Winged sexual forms develop in late summer that mate and females return to winter host crops to lay eggs.

For more information about pea aphids, see our Insect of the Week page!

Pea aphid adult (L) and nymph (R)
©Mike Dolinski, MikeDolinski@hotmail.com

Winter Update – 2017 Pea leaf weevil distribution map for SK

The 2017 Saskatchewan Pea leaf weevil distribution map was recently posted by Saskatchewan Agriculture. The survey is based on the average number of feeding notches observed per plant (read more about PLW monitoring). Watch for the November issue of Agriview when the 2017 map below will be posted accompanied by a written summary.

Participants involved with the survey are thanked for their efforts and the extra sites that produced the 2017 pea leaf weevil map!

The effort revealed a marked expansion in distribution within Saskatchewan in 2017 compared to 2016!

More information on pea leaf weevil can be accessed by reviewing Week 6 of the Weekly Update!

Remember – a NEWLY UPDATED PPMN monitoring protocol is available! Also refer to the pea leaf weevil page within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available. A review of this insect was published in 2011 by Carcamo and Vankosky in Prairie Soils and Crops.

Insect of the Week – Red clover casebearer moth

This week’s Insect of the Week is the red clover casebearer moth. As it’s name suggests, its primary host is red clover, but larvae also reportedly feed on alsike, stone, white and zig-zag clover. The mature larvae are contained within portable cases made of withered flower petals and silk and they feed from the front end of the case on developing seed in the floret. They can consume up to three seeds per day. In areas with high numbers of these moths, such as the Peace River region in BC and AB, red clover stands should only be grown for one year in rotation.

For more information on the red clover casebearer moth, visit our Insect of the Week page.

Red clover case bearer moth – adult (Tim Haye)

Red clover casebearer moth – sealed overwintering larval cases (Boyd Mori)

Remember the NEW Cutworm Field Guide is free and downloadable in 2017!

Weekly Update – Pea leaf weevil

Pea leaf weevil (Sitona lineatus) – Pea leaf weevils emerge in the spring primarily by flying (at temperatures above 17ºC) or they may walk short distances. Pea leaf weevil movement into peas and faba beans is achieved primarily through flight. Adults are slender, greyish-brown measuring approximately 5 mm in length (Figure 1).

Figure 1. The pea leaf weevil, Sitona lineatus, measures ~5mm long (Photo: H. Goulet).

The pea leaf weevil resembles the sweet clover weevil (Sitona cylindricollis) yet the former is distinguished by three light-coloured stripes extending length-wise down thorax and sometimes the abdomen (Link here for the Pea leaf weevil monitoring protocol with photos of related weevils). All species of Sitona, including the pea leaf weevil, have a short snout.

Adults will feed upon the leaf margins and growing points of legume seedlings (alfalfa, clover, dry beans, faba beans, peas) and produce a characteristic, scalloped (notched) edge (Figure 2). Females lay 1000 to 1500 eggs in the soil either near or on developing pea or faba bean plants from May to June.

Figure 2. Feeding notches on clam leaf of pea plant resulting from pea leaf weevil (Photo: L. Dosdall).

Weekly Update – Pea leaf weevil

Reminder – Pea Leaf Weevil (Sitona lineatus) – Pea leaf weevils emerge in the spring primarily by flying (at temperatures above 17ºC) or they may walk short distances. Pea leaf weevil movement into peas and faba beans is achieved primarily through flight. Adults are slender, greyish-brown measuring approximately 5 mm in length.

The pea leaf weevil resembles the sweet clover weevil (Sitona cylindricollis) yet the former is distinguished by three light-coloured stripes extending length-wise down thorax and sometimes the abdomen (Access the Pea leaf weevil monitoring protocol). All species of Sitona, including the pea leaf weevil, have a short snout.

Adults will feed upon the leaf margins and growing points of legume seedlings (alfalfa, clover, dry beans, faba beans, peas) and produce a characteristic, scalloped (notched) edge. Females lay 1000 to 1500 eggs in the soil either near or on developing pea or faba bean plants from May to June.

Information related to Pea leaf weevil in Alberta and the forecast for 2016 is posted here.