The common name jewel beetle refers to the large group of scarab beetles in the genus Chrysina (used to be Plusiotis). The shiny color reflection on their elytra (fore-wing), mostly green some are silver or gold, earns themselves the beautiful name Jewel Beetle. These beetles are no doubt one of the most attractive insects in the world, and the high market value also lures many hobbyists or professional beetle collectors worldwide to trap them using mercury vapor lamps and black lights. There are approximately 100 species of Chrysina beetles around the world, whereas only 4 species occur in North America, 3 in Arizona and 1 in Texas. Adult beetles emerge during the onset of monsoon season in Arizona sky islands then disappear in the fall when the temperature start to decrease. These beetles overwinter as larval stage (white grub) underground feeding on plant roots and organic matters, pupate in soil in spring then thousands of adults fly out in summer after a heavy soak brought by monsoon.

I chose Santa Rita Mountains as my destination for my first trip of Chrysina exploration, simply because this place is one of the very few locations that you can see three of the Arizona Chrysina species together in one night. This area is also one of the legendary habitats not only for bird watching naturalists but also for beetle collectors. I set up a black light and a HID light in one of the parking area of the valley about 5000 ft elevation, two lights were 10 meters apart from each other. Twenty minutes after 8pm, the first jewel beetle, Chrysina gloriosa, landed on the ground near the HID light. This shining green colored beetle with silver striped on its back totally explains why they are called jewel beetles. In fact, C. gloriosa is the most common Chrysina species of North America where it distributes in the mountains of S.E. AZ, S. New Mexico, and S.W. Texas. Before this beetle arrived, hundreds of other beetles have already occupied my white sheets under the lights, most of them are in the family Cerambycidae and Scarabaeidae.

Chrysina gloriosa

While I was checking on the first jewel beetle ever in my life, a second species C. lecontei arrived! This male C. lecontei is relatively smaller than C. gloriosa (1 inch long), which has dark green body and red legs, lack of silver striped on the elytra makes this species seemly less attractive than C. gloriosa. Chrysina lecontei‘s distribution in Arizona is as widespread as C. gloriosa but less common in most of area. The next two hours both my HID and black light were attacked by a crowd of Chrysina beetles, including the 3^rd species C. beyeri. This species is the largest jewel beetle in North America (~1.5 inch) and the apple green elytra with purple legs match perfectly on this spectacular beetle. The distribution of C. beyeri is limited to certain mountain ranges in the southern most Arizona such as Huachuca Mountains, Patagonia Mountains, and Santa Rita Mountains. Limited distribution makes C. beyeri more desirable and mysterious among beetle hobbyists. However, in a warm summer night C. beyeri may come to the black light as abundant as C. gloriosa if you are in the right habitat! Although Chrysina jewel beetles are still quite abundant in Arizona sky islands, they are facing heavily and overly collected due to their commercial value. Further research on their biology and ecology should be conducted in the future and the act of protection for these beautiful insects may be considered.

Chrysina beyeri

Further reading: Jewel beetle on National Geographic: http://ngm.nationalgeographic.com/ngm/0102/feature3/

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A Probable Case of Glyphosate Resistant (GR) Palmer Amaranth in Arizona

A probable case of glyphosate (Roundup) resistant Palmer amaranth (i.e., carelessweed or pigweed) has been discovered in Arizona although seed collection and testing are needed to confirm this conclusion. Resistance occurred in no-till cotton where glyphosate was the only herbicide used.

What can we do?

1. In-field Sanitation
1. Hand remove any Palmer amaranth escapes in the field or on the ends of fields - do not allow pollen spread or seed production. Plants with large diameter stems will resprout when cut; regrowth must be controlled.
2. Clean all equipment before leaving fields where Palmer amaranth plants are growing. Remove all plant parts including seeds and soil from machinery before leaving infested fields - do not transport seeds to other fields. Harvest machines have the potential to spread resistant seed if Palmer amaranth plants with seed are present at harvest.
2. Farmstead Areas
1. Palmer amaranth plants growing along irrigation ditches, canals, fence lines, farm roads and equipment yards can be a source of glyphosate resistance genes. Kill all Palmer amaranth plants on the farm with burn-down herbicides (e.g., Aim, ET or paraquat), propane or mechanical means to stop pollen and seed production.
3. Community Action
1. Palmer amaranth infestations on public roads, other public rights-of-way and in residential enclaves scattered around Buckeye can also be reservoirs of resistance genes. The extent to which Buckeye farmers can prevail upon their local government entities and neighbors to control Palmer amaranth may impact the spread of glyphosate resistance.

Consequences

The challenge of limiting the spread of glyphosate-resistant (GR) Palmer amaranth is great. It can be managed in cotton using a diversity of herbicide mechanisms of action and weed control practices. However, cotton growers with GR Palmer amaranth infestations will face greater weed control costs, will be using herbicides and control techniques that require greater management input, will be using hand labor to remove Palmer amaranth escapes and will likely have to use more in-season tillage for weed control.

If you are suspicious of any similar situation or need help, call or email one of the UA faculty listed below:
Bill McCloskey wmcclosk@ag.arizona.edu, Office: 520-621-7613
Randall Norton rnorton@ag.arizona.edu, Office 928-428-2432 - Cell 928-651-0420
Ayman Mostafa ayman@cals.arizona.edu, Office 602-827-8200 ext. 313 - Cell 602-290-8061

To contact Marco Peña go to: marcop@ag.arizona.edu

For questions or comments on any of the topics please contact Marco Pena at the Yuma Agricultural Center.
College of Agriculture, The University of Arizona, Tucson, AZ.